import {DEFAULT_MIME_TYPES} from './mime-default';

export function toFileWithPath(file: File, path?: string, h?: FileSystemHandle): FileWithPath {
    const f = file as FileWithPath;
    const {webkitRelativePath} = file;
    const p =
        typeof path === 'string'
            ? path
            : // If <input webkitdirectory> is set,
              // the File will have a {webkitRelativePath} property
              // https://developer.mozilla.org/en-US/docs/Web/API/HTMLInputElement/webkitdirectory
              typeof webkitRelativePath === 'string' && webkitRelativePath.length > 0
              ? webkitRelativePath
              : `./${file.name}`;
    if (typeof f.path !== 'string') {
        // on electron, path is already set to the absolute path
        setObjProp(f, 'path', p);
    }
    if (h !== undefined) {
        Object.defineProperty(f, 'handle', {
            value: h,
            writable: false,
            configurable: false,
            enumerable: true
        });
    }
    // Always populate a relative path so that even electron apps have access to a relativePath value
    setObjProp(f, 'relativePath', p);
    return f;
}

export interface FileWithPath extends File {
    readonly path: string;
    readonly relativePath: string;
    readonly handle?: FileSystemFileHandle;
}

/**
 * Sets a File's `type` from its extension using the provided `mimeTypes` lookup,
 * but only when the browser didn't already set a type. Returns the same File.
 */
export function withMimeType(file: File, mimeTypes: Map<string, string> = DEFAULT_MIME_TYPES): FileWithPath {
    const {name} = file;
    const hasExtension = name && name.lastIndexOf('.') !== -1;

    if (hasExtension && !file.type) {
        const ext = name.split('.').pop()!.toLowerCase();
        const type = mimeTypes.get(ext);
        if (type) {
            Object.defineProperty(file, 'type', {
                value: type,
                writable: false,
                configurable: false,
                enumerable: true
            });
        }
    }

    return file as FileWithPath;
}

function setObjProp(f: FileWithPath, key: string, value: string) {
    Object.defineProperty(f, key, {
        value,
        writable: false,
        configurable: false,
        enumerable: true
    });
}